Carriage mounting for lift truck



July 17, 1962 Filed May 241 1961 G. F. QUAYLE CARRIAGE MOUNTING FOR LIFT TRUCK 2 Sheets-Sheet 1 INVENTOR. GGQQGE 1'". Quaycf July 17, 1962 Filed May 24, 1961 G. F. QUAYLE CARRIAGE MOUNTING FOR LIFT TRUCK 2 Sheets-Sheet 2 INVENTOR. Geog-3e fi QUAYLE ATTOAWVIFY 3,044,576 CARRIAGE MOUNTING FOR LIFT TRUCK George F. Quayle, Philadelphia, Pa, assignor to The Yale and Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Filed May 24, 1961, Ser. No. 112,249 6 Claims. (Cl. 187-9) This invention relates to a lift truck, and in particular to adjustable anti-friction means for guiding the vertically movable load supporting structure of such a truck.

It is common practice to utilize anti-friction means, such as rollers or slide bearings, to facilitate the vertical movement of one upright of a lift truck relatively to another, or the vertical movement of a load carriage on the uprights. In many instances, it has been found desirable to provide for adjustment of the anti-friction means to take up, or limit, the play or movement between the members, and various arrangements have been proposed heretofore for this purpose. For example, in United States Patent No. 2,059,150, it was proposed to mount the anti-friction rollers on pivots eccentrically placed on rotatable mounting members whereby the pivots could be adjusted by rotation of the mounting members. Such an arrangement, however, is necessarily expensive as it not only requires rotatable mounting members for the roller pivots, but it also requires some type of-clamping means to lock the mounting members in adjusted positions.

As an alternative arrangement, it has been proposed to fix the roller pivots on which the rollers are to be mounted, and then select rollers of the proper diameters from a series of rollers of different diameters to obtain the desired adjustment. This arrangement has the advantage that the roller pivots may be rigidly fixed, as by welding, thereby providing cheaper and stronger mounting of the roller pivots. Such arrangement, however, has a disadvantage in that a series of comparatively expensive rollers of different diameters must be stocked in order to provide a range of adjustment.

The purpose of this invention is to provide adjustable anti-friction means having the advantage of fixed mountings and also the advantage of adjustability without the necessity of substituting anti-friction means of different sizes.

To this end, the anti-friction means of the invention include a slide bearing having a polygonal outer periphery providing a plurality of bearing surfaces engageable one at a time with a guiding surface of the mast of the truck. Cooperating means are provided on the slide bearing'and on the load supporting member for supporting the slide bearing in. various rotated positions about a fixed axis which is eccentric to the outer periphery of the slide bearing. By this arrangement, each of the bearing surfaces is at a difierent distance from the fixed axis and the spacing between the fixed axis and the bearing surface engageable wi h the guiding surface of the mast may be readily adjusted merely by changing the rotated position of the slide bearing to bring a difierent bearing surface thereof into a position for engagement with the guiding surface of the mast. The slide hearing may, therefore, be easily adjusted not only during fabrication of the truck, but also when the truck is in use in the field and adjustment becomes necessary due to wear.

While the adjustable anti-friction means of the invention may be used between any of the relatively movable parts of the load supporting structure of the truck where rollers are commonly used, it isparticularly useful in guiding and accepting stresses between the load carriage and the mast in a transverse, or sidewise, direction so as to prevent transverse movement or cocking of the load carriage by off-centered loads. This invention is accordingly ice illustrated in the drawings and described hereinafter in conjunction with such use.

In the drawings:

FIG. 1 is a side elevation view of a lift truck incorporating adjustable anti-friction means in accordance with the invention to prevent traverse cocking of the load carriage;

FIG. 2 is a sectional view taken on the line 22 of FIG. 1, showing the slide bearings constructed in accordance with the invention mounted on existing roller shafts secured to the load carriage of the truck;

FIG. 3 is a sectional view taken on the line 33 of PEG. 2;

FIG. 4 is a view similar to that of FIG. 3, but showing only the left-hand portion thereof with parts removed to show more clearly the engagement of the slide bearings with the guiding surfaces of the mast;

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4;

FIG. 6 is an enlarged elevational view of one of the slide bearings removed from the pivot;

FIG. 7 is a slightly modified form of slide bearing adapted for new truck construction; and,

FIG. 8 is a sectional view taken on the line 8-8 of FIG. 7.

Referring 'to the drawings, and in particular to FIG. 1, there is shown a lift truck T of the type disclosed in United States Patent No. 2,759,562, except that the usual anti-cocking rollers for preventing transverse cocking of the load carriage have been replaced by adjustable slide bearings constructed in accordance with the invention.

The load carriage of the truck is shown at 10 mounted for vertical movement on the secondary uprights 11 of the truck by means of rollers 12, shown in FIG. 2, which are secured to brackets 13 and extend into the channels of the secondary uprights 11. The uprights 11 in turn are mounted for vertical movement on primary uprights 14 by rollers 15.

Adjustable slide bearings constructed in accordance with the invention are shown at16 mounted on the stub shafts or pivots 17 which would normally carry anticocking rollers for engaging inner and outer guide surfaces 18 and 19 0f the secondary uprights 11. As best shown in FIG. 3, there are two upper and two lower pivots 17, each welded or otherwise rigidly secured to the back plate 24) of the load carriage 10. As best shown in FIGS. 5 and 6, each slide bearing 16 is provided with a cylindrical hole 21 by which it is mounted on a pivot 17.

Each of the slide bearings 16 is of square section so as to provide four outer bearing surfaces 22 adapted to be selectively presented for engagement with one of the guiding surfaces 18 and 19 of the secondary uprights. The bearing surfaces 22 of the slide bearings 16 mounted on the upper pivots 17 are adapted to engage the opposed inner guide surfaces 18 ofthe secondary uprights 11, and the bearing surfaces 22 of the slide bearings 16 mounted on the lower pivots 17 are adapted to engage the outer guide surfaces 19 of the secondary uprights 11. It will be appreciated that engagement of the bearing surfaces of the slide bearings with the inner and'outer guide surfaces 18 and 19 limits transverse, or sidewise, cocking of the load carriage by off-centered loads.

In accordance with the invention, the slide bearings 16 are so constructed that they may be adjusted to take up play between the load carriage 10 and the secondary uprights 11 in a transverse direction. Such adjustment is provided for in the form of the slide bearings as shown in FIGS. 26 by drilling the cylindrical mounting hole 21 of each slide bearing 16 off-center relatively to the outer hearing surfaces 22. This is :best illustrated in FIG. 6 in which sesame indn'cal hole 21 ad the centerlines C-C and D-D define the geometrical center of the four bearing surfaces 22. Thus, when each of the slide bearings 16 is mounted on its respective pivot 17, the fixed axis X-X of the pivot 17 is eccentric to the outer periphery of the slide bearing and each of the bearing surfaces 22 thereof is at a different distance from the fixed axis X-X of the pivot 17. Each slide bearing 16, therefore, may be adjusted to take up play between the load carriage and the secondary uprights 11 in the transverse direction by removing the slide bearing 16 from its pivot '17, rotating the slide bearing to bring a different bearin g surface 22 spaced a greater distance from the axis of the pivot 17 into a position for engagement with the guiding surface of the upright 11, and then remounting the slide bearing on the pivot in this position. As there are four bearing surfaces 22, four points of adjust ment are thus provided. Each of the slide bearings 16 is adapted to be retained on its respective pivot 17 by means of a removable clip 23, as best shown in FIGS. 4 and 5.

Each slide bearing 16 may be easily fabricated from square steel bar stock to which a bronze tube has been welded or otherwise secured so that, as best shown in FIG. 6, the resulting slide bearing has a steel center portion 24 and a bronze outer bearing portion 25 forming the bearing surfaces 22 to provide the desired bearing properties.

Referring now to FIGS. 7 and 8, there is shown a slightly modified form of the adjustable slide bearing of the invention. form .is particularly useful for new truck construction because it eliminates the expensive roller pivots 17.

In this form of the invention, a supporting post 26, formed from hexagonal steel bar stock and welded or otherwise secured to the back plate 20 of the load cari i-age, is used in place of the roller pivots 17. To facilitate the welding of the supporting post 26 to the back plate and to eliminate the presence of weld metal on the outside of the supporting post, a hole 27 is drilled through the supporting post so that the post may be welded to the back plate within the hole, as indicated at 28- in FIG. 8.

The post 26 supports a slide bearing 29 in the form of a hexagonal bronze sleeve or bushing which is eccentrically extruded so that each of the six sides of the sleeve has a diiferent i wall thickness. Thus, when the slide bearing 29 is mounted on the hexagonal supporting post 26, each of the six outer bearing surfaces 30 is at a different distance from the axis ZZ of the supporting post 26. The slide bearing 29'therefore, may be easily and quickly adjusted to take up play between the load carriage and the secondary upright by removing the slide bearing to bring a different bearing surface 3d" spaced a greated distance from the axis ZZ into a position for engagement with the guiding surface of the secondary upright 11, and then remounting the slide bearing on the supporting post 26 in this position. As there are six outer bearing surfaces 30, six points of adjustment are provided. 7

Each of the sides of the slide bearing 29 is provided with a hole 31 which is adapted to align with a hole .32 through the supporting post 26, and the slide bearing 25) is adapted to be retained on the supporting post 26 by a removable pin 33 inserted through aligned holes 31 in the bearing slide and the holes 32 in the supporting post.

From the preceding description, it can be seen there is provided very simple, inexpensive anti-friction-means for the load supporting structure of a lift truck which may be quickly and easily adjusted to take up or limit play between the relatively movable parts of the load supporting structure of the truck. Such adjustment may be easily made duringfabrication of the truck, or at any time thereafter.

While the adjustable anti-friction means of the invention have been described as used in place of rollers for preventing transverse or sidewise cocking of the load carriage of the lift truck, it will be appreciated that they may also be used in place of the rollers for mounting the secondary uprights on the primary'uprights, such as the rollers 15 shown in FIG. 2, or in place of rollers for mounting the load carriage on the secondary uprights, such as the rollers 14- shown in FIG. 2.

It will also be appreciated that while two specific forms of the invention have been shown and described, that this is for the purpose of illustration, and that changes and modifications may be made therein without departing from the spirit and scope of the invention.

I now claim:

1. A lift truck having a mast, a load supporting memoer mounted for vertical movement on said mast, a slide bearing having a polygonal outer periphery providing a plurality of bearing surfaces engageable one at a time with a guiding surface of said mast, cooperating means on said slide bearing and on said load supporting member for supporting said slide bearing in a variety of rotated positions about an axis which is fixed relatively to said load supporting member and is off-center relatively to the outer periphery of said slide bearing whereby each of said bearing surfaces is at a different distance from said axis and said slide bearing may be selectively positioned to present any one of said bearing surfaces for sliding engagement with said guiding surface of said mast to provide adjustment between the load supporting member and the mast.

2. A lift truck having a mast, a load supporting member mounted for vertical movement on said mast, a slide bearing having a polygonal outer periphery providing a plurality of bearing surfaces engageable one at a time with a guiding surface of said mast, said load supporting member having a cylindrical shaft secured thereto, said slide bearing having a cylindrical hole therein for receiving said cylindrical shaft whereby to support said slide bearing on said load supporting member in various rotated positions, said cylindrical hole being off-center relatively to said bearing surfaces whereby when said bearing surface is mounted on said cylindrical shaft each of said bearing surfaces is at a different distance from the axis 1 of said cylindrical shaft and adjustment between said load slide bearing 29 from the supporting post 26, rotating the supporting member and said mast may be obtained by changing the rotated position of the slide bearing on the load supporting member to present a different bearing surface for sliding engagement with said guiding surface of said mast.

3. A lift truck having a mast providing a pair of spaced uprights, a load carriage mounted for vertical movement on said uprights, a slide bearing having a polygonal outer periphery providing a plurality of bearing surfaces engageable one at a time with a guiding surface on said uprights,vcooperating means on said slide bearing and on said loadcarriage for supporting said slide bearing in a variety of rotated positions about an axis which is fixed relatively to said load carriage and is off-center relatively to the outer periphery of said slide bearing whereby each of said bearing surfaces is at a different distance from said axis and said bearing member may be selectively positioned to present any one of said bearing surfaces for sliding engagement with said guiding surface of said uprights to provide adjustment between the uprights and the load carriage. l 4. A lift truck having a'mast, a load supporting member mounted for vertical movement on said mast, a slide bearing having a polygonal outer periphery providing a plurality of bearing surfaces engageable one at a time with a guiding surface of said mast, cooperating means on said slide bearing and on said load supporting member including a hole in said slide bearing and a post on said load supporting member adapted to be received in said hole in said slide bearing to support said slide bearing in a variety of rotated positions about an axis which is fixed 3,244, are

relatively to said load supporting member and is olfcenter relatively to the outer periphery of said slide bearing whereby each of said bearing surfaces is at a different distance from said axis and said slide hearing may be selectively positioned to present any one of said bearing surfaces for sliding engagement with said guiding surface of said mast to provide adjustment between said load supporting member and said mast, said post having a hole therethrough and being welded Within the hole to the load supporting member.

5. A lift truck having a mast, a load supporting member mounted for vertical movement on said mast, a slide bearing in the form of an hexagonal sleeve providing six outer bearing surfaces engageable one at a time with a guiding surface of said mast, a post on said load supporting member for receiving and supporting said sleeve in a variety of rotated positions about an axis fixed relatively to said load supporting member and off-center relatively to said outer bearing surfaces whereby each of said bearing surfaces is at a diiferent distance from said axis and said sleeve may be selectively positioned to present any one of said bearing surfaces for sliding engagement with said guiding surface of said mast to provide adjustment between said load supporting member and said mast.

6. A lift truck having a mast, a load supporting member mounted for vertical movement on said mast, a slide 6. bearing in the form of an hexagonal sleeve providing six outer bearing surfaces engageable one at a time with a guiding surface of said mast, a post on said load supporting member for receiving and supporting said sleeve in a variety of rotated positions about an axis fixed relatively to said load supporting member, said hexagonal sleeve being eccentrically formed whereby each of said bearing surfaces is at a different distance from said axis when said sleeve is mounted on said post and adjustment between said load supporting member and said mast may be obtained by changing the rotated position of the slide bearing on the load supporting member to present a different bearing surface for sliding engagement with said guiding surface of said mast. 

